The present invention relates to a face mask for infants adapted to be mounted on an inhaler device, e.g., an inhaler used to deliver medicaments for the treatment of bronchial diseases such as asthma.
When dealing with bronchial diseases among children and infants, it is difficult to make the patient inhale the therapeutic substances necessary for treatment. When asthma makes its debut among infants and young children, typically at 8 months to 2.5 years, it is especially difficult to make the infant inhale the prescribed medical substances in the proper way. An infant has a limited lung capacity and the force of the infant's breath during inhalation (inhalation flow) is thus limited. This is even more apparent when the infant is suffering from asthma or other bronchial diseases. Parents also desire that the devices used for inhalation be as flexible as possible, as it is difficult to position the inhaler in a way that will allow proper inhalation by an infant.
It is known in the art to use stationary inhalation devices having expensive and complicated face masks which adapt the device for use on infants. Use of a stationary device is inconvenient both for the infant and for the parents as they are bound to these stationary devices which are often placed in hospitals. As the inhalation capacity of an infant is limited, the administration will be time consuming, which of course also is inconvenient.
Thus, inhalation therapy is typically accomplished through the use of portable metered-dose inhalers. A metered-dose aerosol inhaler includes a holder for a medicament dispenser and an extended body, which in the technical field of inhalers normally is called a "spacer" or inhalation chamber, having an outlet provided at the end remote from the dispenser. An inhalation/exhalation valve, e.g., a one-way valve, is typically provided adjacent to the outlet, and at the outlet opening a mouthpiece is provided. When such a device is used by older children or adults the mouthpiece is inserted between the teeth and the lips are closed around the mouthpiece. It is however not possible for an infant to hold such a mouthpiece between its lips. Moreover, these devices are constructed to be used by older children who have large lung capacity and who can inhale more forcefully. The inhalation/exhalation valves provided typically require a certain inhalation flow, which an infant is unable to generate, to open properly. Therefore, for satisfactory inhalation to be achieved by infants, these inhalation devices generally must be provided with a face mask.
Face masks have thus been proposed which include an annular adaptor part which is to be connected to one end of the body of the inhalation device or spacer, and a face engaging portion which is joined with one end of the of the adaptor part. EP 0 344 879 and EP 0 384 050 describe face masks for use with a device for inhalation of aerosols. These face masks present a rather large "dead space" between the valve in the spacer and the face mask, requiring a certain inhalation flow to insure that the substance to be inhaled does not stay in this "dead space", but reaches the lung area. Moreover, the shape of these face masks is not adapted to the face of an infant as it is round and the inhalation device is to be held in a horizontal position which makes inhalation difficult for an infant. Thus neither of these two known devices is designed for the special needs of infants who are suffering from bronchial diseases.